The Safety of Dietary Supplements

Dietary supplement safety should be of primary concern to consumers. Because they are assumed to be safe unless proven otherwise, dietary supplements present special safety challenges. In 2000 the FDA received 500 dietary supplement adverse event reports; that number rose to 553 in 2001 and to 1214 in 2002. Adverse events caused by dietary supplements vary from mild to severe and may be influenced by individual health status (medical history and genetic makeup), dietary supplement composition and dosage (including levels of active and inactive ingredients), and concomitant consumption of other substances (including foods, beverages, over-the-counter and prescription drugs, and other dietary supplements).

Health Status
Dietary supplements may act differently in different people. As noted by Christine Lewis-Taylor, former director of the FDA's Office of Nutritional Products, Labeling, and Dietary Supplements, "one man's dose can be another man's poison." An individual's genes and health status help to explain this difference.
Nutritional genomics and metabalomics are growing areas of research that explain the relationship between genetic makeup and nutrition- and metabolism-related outcomes.
Certain relationships between nutrients and health outcomes are well characterized. Folate supplementation, for example, is recommended for all women of childbearing age to prevent fetal neural tube defects. By isolating and analyzing the function of the genes responsible for folate metabolism, however, scientists have identified a genetic variation that predisposes some women to give birth to babies with neural tube defects. This knowledge may eventually allow scientists to target folate supplementation to at-risk individuals.
Stage of life, medical history, and environmental factors such as diet and exercise can affect how a dietary supplement behaves in the body. Several populations are at increased risk of adverse effects of dietary supplements:
· children,
· people of smaller stature,
· elderly people,
· women who are pregnant or breastfeeding,
· people with immune disorders (for example, HIV or AIDS),
· people with cancer,
· malnourished people,
· people with existing or subclinical liver or kidney disease,
· people with a history of gastrointestinal health conditions (such as Crohn's disease) or surgery (such as gastric bypass surgery),
· people who are hospitalized,
· transplant recipients,
· surgical patients.

While research has revealed the unique nutritional needs in women of childbearing age (for example, 400 micrograms
of folate are recommended to prevent neural tube defects in offspring, and if pregnant, supplemental vitamins are recommended), information on the effects of dietary supplements during pregnancy and breastfeeding are extremely limited. This is largely due to ethical considerations: scientific studies are not conducted during pregnancy and breastfeeding because of potential risks to the women and their babies. Several herbal dietary supplements historically used during pregnancy have been identified as harmful